Hiya hun, hope you're doing ok. I don't want to be a party pooper but I have been on here so long and have seen lots of women get pos opks just before AF, I feel bad saying it but I just don't think its reliable enough, I never use them around AF time for this reason. I really do think you should test as soon as possible to stop the worry and stress.
Its great though that it hasn't turned into full flow and I have my fingers crossed for you xx